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Re: Needless DNS queries

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On Tue, Jun 07, 2022 at 11:22:34AM -0400, Dan Ritter wrote:
> 
> search		Search list for host-name lookup.  By default, the search
>  [...]
> 	This may be changed by listing the desired domain search
> path following the search keyword with spaces or tabs separating the
> names.  Resolver queries having fewer than ndots dots (default is
> 1) in them will be attempted using each component of the search path in
> turn until a match is found.

I've read this paragraph a few times, and as far as I can tell, it's
simply wrong.

If you go down farther in the page and look at:

              ndots:n
                     Sets a threshold for the number of dots which must appear
                     in a name given to res_query(3) (see resolver(3))  before
                     an  initial absolute query will be made.  The default for
                     n is 1, meaning that if there are any dots in a name, the
                     name  will  be tried first as an absolute name before any
                     search list elements are appended to it.  The  value  for
                     this option is silently capped to 15.

This one says that it simply determines whether the name will be tried
as is *before* appending the search domain(s) to it, or whether it just
skips straight to appending the search domains.

My experience, and the OP's experience, suggests that the description in
the ndots paragraph is correct, and the description in the search paragraph
is not.

To the best of my knowledge, there isn't any setting to *prevent* the
appending of search domains to a name, no matter how many dots you put
in the name.

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Thread

Needless DNS queries Dieter Rohlfing <dr-erc@gmx.net> - 2022-06-07 17:10 +0200
  Re: Needless DNS queries David Wright <deblis@lionunicorn.co.uk> - 2022-06-07 17:30 +0200
  Re: Needless DNS queries Dan Ritter <dsr@randomstring.org> - 2022-06-07 17:40 +0200
    Re: Needless DNS queries Tim Woodall <debianuser@woodall.me.uk> - 2022-06-07 18:10 +0200
    Re: Needless DNS queries Greg Wooledge <greg@wooledge.org> - 2022-06-07 19:00 +0200
      Re: Needless DNS queries Darac Marjal <mailinglist@darac.org.uk> - 2022-06-07 19:40 +0200
        Re: Needless DNS queries Lee <ler762@gmail.com> - 2022-06-08 00:10 +0200
      Re: Needless DNS queries Tim Woodall <debianuser@woodall.me.uk> - 2022-06-08 00:20 +0200
        Re: Needless DNS queries Lee <ler762@gmail.com> - 2022-06-08 03:00 +0200
          Re: Needless DNS queries Greg Wooledge <greg@wooledge.org> - 2022-06-08 03:10 +0200
            Re: Needless DNS queries Lee <ler762@gmail.com> - 2022-06-08 07:30 +0200
  Re: Needless DNS queries Dieter Rohlfing <dr-erc@gmx.net> - 2022-06-14 15:10 +0200

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